Prominent Crista Terminalis Mimicking Right Atrial Thrombus in a Case of Permanent Pacemaker Implantation - Role of Two- and Three-Dimensional Transesophageal Echocardiography.

Crista terminalis is a crescent-shaped fibromuscular ridge in the posterolateral wall of the right atrium (RA) which separates the smooth posterior region of RA from a more muscular anterior region. When prominent, it frequently mimics RA thrombus, vegetation, or tumors such as myxoma. Differentiation of such anatomical structural variations from other masses is vital to minimize misdiagnosis and avoid disease-related apprehension. Different diagnostic modalities may be needed which have their own imaging characteristics as well as limitations. Our case emphasizes the differentiating features of prominent crista terminalis using two-dimensional and three-dimensional transesophageal echocardiography.